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Flashcards in Molecular Genetics Deck (15)
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1
Q

Which of the following statements about DNA annealing is false?

A

pairing hydrogen bonds to complementary sequence, prevent bonds from reforming, single-strand binding proteins bind to exposed strands of DNA to block the hydrogen bonds from reforming

2
Q

The nucleotide at the end of one strand of a fragment of double-stranded DNA has a free phosphate attached to the 5’ carbon of its deoxyribose sugar. The complementary nucleotide has:

A

a hydroxal group attached to the 3’ carbon of its deoxyribose sugar

3
Q

Which of the following statements is false regarding the discovery of the model of DNA…

A

Friedrich Mieschner – isolated non-protein (puss)
Fredrick Griffith – mouse experiment
Hammerling – algae expirement
Avery, McCarty, MacLeod – destroyed lips, proteins, carbs, nucleic acids = transformation – destroyed DNA = no transformation
Chargraff – A=T, C=G
Hershey + Chase – used radioactive sulfur and phosphorus to tag virus
Rosalind Franklin + Maurice Wilkins – x-ray of DNA
Watson + Crick – made model of DNA, discovered the hydrogen bond

4
Q

During DNA replication, one of the new strands of DNA is synthesized continually, while the other synthesized as a number of separate fragments of DNA that are subsequently linked by DNA ligase. This is because:

A

DNA polymerase III only synthesizes DNA in the 5’ – 3’ direction

5
Q

An enzyme, which excises a mismatched base in a newly synthesized strand of DNA, is called:

A

an exonuclease

6
Q

In what order do the following molecules become involved in DNA replication in E. Coli?

A

Helicase, single-strand binding proteins, primase, DNA polymerase III

7
Q

Which of the following correctly describes the order in which cell components become involved in protein synthesis?

A

DNA, mRNA, ribosome, tRNA

8
Q

Line A below shows the peptide synthesized after transcription and translation of a piece of DNA. Line B shows the peptide synthesized after a mutation in this piece of DNA.

A

Proline – arginine – aspartic acid – lysine – alycine
Proline – glutamine – aspartic acid – lysine – glycine
A. base substitution

9
Q

In eukaryotes, introns are removed before mRNA leaves the nucleus because:

A

they do not code for protein

10
Q

Which is the correct sequence for the enzymes listed in DNA replication?

A

gyrase, helicase, single-stranded binding proteins, primase, DNA polymerase III

11
Q

Compare the original (right) and copied (left) mRNA sequences below. This change could be a result of:

A

AUAUUCGGCAAUCCG
AUAUUCCGCAAUCCG
A. point mutation

12
Q

Spliceosomes remove introns from a mRNA. This offers the possibility of control at which of the following levels?

A

transcription

13
Q

The “Central Dogma” states that the flow of genetic information is in the direction…

A

DNA, RNA, protein

14
Q

There are three kinds of RNA polymerase in eukaryotes-RNA polymerase I, II and III. RNA polymerase I, II, and III are used, respectively, to transcribe:

A

rRNA, mRNA, tRNA

15
Q

The function of the cap and poly-A tail is added to mRNA in eukaryotic cells is to…

A

prevent degradation of the mRNA